Muslims, the world's second-most prevalent religion, are also the youngest religious group, according to a new study from the Pew Research Center. (AP photo / Prakash Hatvalne)

HUNTSVILLE, Alabama – The “Global Religious Landscape,” as the title of a study released Tuesday, Dec. 18, 2012, paints it, is dotted with young Muslims and Hindus, old Buddhists and Jews -- and way more non-affiliated people than previous studies have shown.

The annual global study by the Pew Research Center found that one in six people worldwide, while sometimes affirming a sense of religiousness or belief in a deity, do not identify themselves with any religion. The study’s numbers are current as of 2010.

The study did not track religious practice or service attendance, just self-identification.

The study also tracks the median age of religious groups, where faith groups are located and who lives as a minority faith -- about one-fourth of the world's people.

If one-in-six, or about 16 percent of the world’s population, .1 billion people, is unaffiliated, that makes the unaffiliated the third largest group worldwide. As a group, the unaffiliated rank after Christians (32 percent of the world’s population and 2.2 billion people) and Muslims (23 percent, 1.6 billion). Hindus are 15 percent, 1 billion, and Buddhists, 7 percent, are about 500 million people.

Those following traditional religions such as African, Chinese, Native American and Australian aboriginal faiths, together number about 400 million, or 6 percent of the world’s population.

There are about as many unaffiliated people in the world are there are Catholic Christians. It’s the first time, according to Conrad Hackett, one of the primary researchers on the study who talked with The New York Times, that survey data was analyzed to provide reliable estimates for the unaffiliated. Most unaffiliated people live in Asia, especially in China.

Groups with less than 1 percent of the population include Jews, with 14 million or 0.2 percent – about the same number as members of the Church of Jesus Christ of Latter-day Saints – and also Baha’is, Jains, Sikhs, Shintoists, Taoists, Wiccans and Zoroastrians.